import java.util.Arrays;
import java.util.Scanner;

public class Main  {
    public static void main(String[] args) {
        task2();
    }

    static void task1() {
        Scanner input = new Scanner(System.in);
        String data = input.nextLine();

        int day1 = Integer.parseInt(data.split(" ")[0]);
        int day2 = Integer.parseInt(data.split(" ")[1]);

        if (day1 > 7) {
            System.out.println(day1 - 7);
        } else {
            System.out.println(day2 + 7);
        }
    }

    static void task2() {
        Scanner input = new Scanner(System.in);
        String data = input.nextLine();

        int cntA = 0, cntAB = 0, cntABC = 0;

        for (char c : data.toCharArray()) {
            if (c == 'a') {
                cntA++;
            } else if (c == 'b') {
                cntAB += cntA;
            } else if (c == 'c') {
                cntABC += cntAB;
            }
        }

        System.out.println(cntABC);
    }
}